Apparatus for silencing and exhausting gases and method therffor



C. L. STOKES.

APPARATUS FOR SILENCING AND EXHAUSTING GASES AND METHOD THEREFOR- APPLICATION HLED on. 21. 1917.

1,382,690. Patented June 28, 1921.

INVENTOR UNITED si'rA 'res PATENT, OFFICE.

CHARLES LAWRENCE-STOKES, OF YORK, N. Y.

Specification of Letters Patent, Patented J n 28, 1921 Application filed October 27, 1917; Serial No. 198,802.

To wllwhomz'tmag concern: p

"Be it known that I, CHARLES LAWRENCE STOKES, a citizen of the United States, re-

siding at New York, in the county of New Yorkand State of New York, have invented certain new and useful Improvements in Apparatus for Silencing and Exhausting Gases. and Methods Therefor, of which the following is a specification. 10

This invention relates to mufflers for internal combustion engines and can also be applied as a silencer for guns. It is well known that the passage of gases underpressure through a confined space induces a vacuum following the path of these gases and this fact is used in this invention to utilize this vacuum to induce currents of air to flow from the external portion of the apparatus to the internal which the gases are forced.

It is an object of this invention to provide asimplifiedand cheap means of bringing the air in so thatit will mingle under vacuum or pressure with the gases and so break up the sound waves as to silence them and also under certain conditions to exhaust the gases by induced vacuum.

The invention is particularly applicable to internal combustion engines used in aeroplanes. It is well known that an aeroplane, to sustain itself in the air must move at a high rate of speed and the speed of the aeroplane moving through the air will give-a igh pressure and large volume of air which can be used in the apparatus in addition to the vacuum induced by the engine gases themselves to aid exhaust. One of theprincipal objections ,to using well known types of mufllers on aeroplanes has been that the ordinary type of muffle'r causes what is known as back pressurebn the engine cylinders and consequently loss of power. It will be readily understood that a muffler, which in addition to being an effective silencer can do away with this back pressure by using the ejector action of air caused by the high speed at which the aeroplane is traveling, will be highly desirable.

portion through Referring to the drawing, 1 is the exhaust pipe. of an internal combustion engine or it may be a gun or rifle barrel. To the end of this is secured or fastened in a suitable manner a casing 2. This casing is preferably of a conical form and has projecting through it at different portions, conical shaped tub'es. These tubes may be arranged symmetrically 13 of preferably larger diameter than that of the interior 5 of pipe 1. This is in order that the volume of gases passing through 1 together with the air drawn in through tubes .3 shall have room to freely pass out at the nitzuth 4 thus eliminating any back'pressure w atsoever. The operation is as follows: Exhaust gases or rifle bullets passing through pipe 5 into the interior of casing 2 and passing out of mouth 4 to the atmosphere induce a certain amount of vacuum on the interior of easing 2. This vacuum acts upon the interior mouths of tubes 3 and causes a certain volume of air to rush'in through the exterior mouths of tubes 3, to theinterior of casing 2. This body of air rushing in at a plurality of points approximately concentric with the passage-way of the gases, mingles with the exhaust gases thus causing sound waves created by the explosion. of the motor or the rifle to be broken up and passed quietly to atmosphere.

In an aeroplane which is moving at high velocity, the volume of air passing through from the exterior to the interior of casing 2 will be very much larger and under comparatively high pressure. It will therefore be seen that the velocity of this air w1ll througli passage 5 and will eliminate back pressure in passage 5 as well as'silencing the said pipe, said casing having at least one face thereof inclined tothe longitudinal axis or staggered. Casing 2 has an outlet 4 which cause an ejector-action on the gases passing of said pipe and casing, and a plurality of air inlet tubes extending into said casing fromthe inclined face thereof at an acute angle to said longitudinal axis. I

Q Thacombination as claimed in clalm '1, wherein the said casing is of conical form,

and said pipe. communicates with the smaller end of the casing, the air inlet tubes extending into said casing from all parts of the conical wall thereof.

3. The combination as claimed in claim 1, I

wherein thesaid casing is of conical form and said pipe communicates with the smaller end of the casing, the air inlet tubes extending into said casing from all parts of the conical wall thereof, the wall of the casing remote from said pipe belng conical and providedwith an aperture which s of at least the same size as the interior diameter of said ipe.

4. The met 0d of exhausting gases, wh1ch consists in introducing said gases into a chamber of increasing cross-sectional area, and introducing cool air into said chamber through a plurality of separate and independent passages extending into said chamher from the exterior thereof at anacute angle to the'longitudinal axis thereof.

5. The method of exhausting gases, which consists in introducing said gases into a.

chamber of increasing cross-sectional area, and introducing a plurality of separate and independent streams of cool air into said chamber from the exterior thereof at an acute angle, to the longitudinal axis thereof.

6. The method of exhausting gases, which consists in introducing said gases into a chamber of increasing cross-sectional area, and introducing a plurality of circular series of converging streams of cool air into said ases from the exterior of said chamber, t e streams of the several series .converging toward points spaced from each other along the axis of the chamber in the direction of flow of the gases.

7. The combination as claimed in cla-iml, wherein a plurality of circular series of air inlet tubes are provided, the series being located one in advance of another in the direction of flow of the gases, the tubes of. each series converging toward a point on the axis of the chamber.

8. The combination as claimed in claim 1, wherein each air inlet tube is of gradually decreasing cross-sectional area in the direction of flow of the air therethrough.

munication with a. main 9. Apparatus for exhausting gases, comprising a chamber through which the gases flow, and a plurality of air passages tapering in the direction of movement of the air therethrough and communicating at the portions of least cross-sectional area with said ch amber.

10. Apparatus for exhausting gases, comprising a chamber connected to the source of supply of said gases, and a plurality of air passages through which air is forced,

said passages communicating with the ingreatest cross-sectional area at their inlet ends and of least cross-sectional area at their points of communication with said main passage.-

12. The method of. exhausting gases, which consists in forcin air through a plurality ofair passages 0% gradually decreasing cross-sectlonal' area in the direction .of movement of the air, and which are in compassage at their points of least cross-sectional area.

In testimony whereof I aflix my signature in presence of two witnesses.

CHARLES LAWRENCE STOKES.

\Vitnesses:

- Gno. L. En'rz, G. G. QUINN. 

